Pilot Clinical Trial to test the function of a Diagnostic Sensor in predicting Impending Urinary Catheter Blockage in Long-term Catheterized Patients

Abstract

AbstractTrial designPilot feasibility trial.MethodsParticipantsadults attending the Outpatient Urology Clinic, having a long-term indwelling urinary catheter and have the mental capacity to consent. Consent for the donation of the urinary catheter and drainage bag were gained at the Urology Clinic, Royal United Hospital (RUH) Bath, alongside a quality-of-life questionnaire.Interventionsthere was no direct intervention to the participants, the trial was to test the functionality of the diagnostic sensor, there was no change to the participant’s medical care.Objectivesrecruitment of 48 participants to donate catheter and drainage bags (including re-recruits); assess the functionality of the sensor to predict impending catheter blockage in human urine; assess the functionality to release at pH > 7; and assess the microbiological profile of the patients with long-term catheters.Outcomedetermination of whether the participant had a blockage event 3 weeks post catheter change, and whether this matched with the result from the sensor. Measurements of the participant’s urine to assess whether the sensor could detect human urine at a pH > 7. Determine the microbial species present in the drainage bag of the participants.ResultsRecruitmentreceived 35 samples from 28 individuals.Outcometwo participants reported blockage events which were successfully detected by the sensor. However, the sensor also predicted blockage in participants that did not block within the 3-week report time period, sensitivity = 100%, specificity = 58.06%. The functionality of the sensor to detect urine above pH > 7 had a sensitivity = 78.75% and a specificity = 96.77%, which gave ap= 2.06×10−24(χ2test). Inclusion of the maintenance solution prescribed to participants, to test the predictability of the sensor, gave a sensitivity = 100%, and a specificity = 62.95%,p= 0.029 (Fisher Exact test). Microbiological analysis indicated thatProteusspp. andPseudomonasspp. were the most commonly isolated microbes.HarmNo adverse events.ConclusionsThe sensor can predict participants more prone to catheter blockage, and it is accurate in detecting urine with a pH >7. Owing to the small sample number of this trial, the results are not statistically powered. However, the data can be used to improve the design of the sensor and inform the design of a larger, randomized clinical trial.Trial registrationTrial was ethically approved by the Research Ethics Committee (REC) number: 20/LO/0094. Integrated Research Application System (IRAS) number: 261095.Fundingtrial was funded by the Urology Foundation and an IAA seed grant, University of Bath.